The first thing I built is this power supply and shortly afterwards I was in desperate need of a good bread board. I've had lots of interesting experiments with these two absolutely indispensable items.
It wasn't long before I was designing an alarm system with discrete logic components in CMOS, and later, in school, a programmable chess clock. Both worked, and the chess clock became the chosen subject of my efforts to do something with a microprocessor. I bought a Z80, inserted it right down into the battle fields of my bread board and started working.
Then suddenly, my bag with six months of hard work and some 20 pages of hand written assembly, the TTL Data Book and some other stuff, was stolen on a train. What a disaster! To be able to recover in time before school was over, I had to buy a computer. I chose the NASCOM 2 and now I was really caught. Thanks to the battery backup on the bread board I could read the program code off the 6117s and from then on I practically never left my NASCOM. Now I could do some really fun projects. This experiment actually was a working chess clock. Did I have fun back then!
Just having discovered the wonderful world of assembly language programming, I began to design a thing I called Telemind. It measures the cost of telephone calls, which was a complicated thing to do in those days, because the cost varied over time of day and distance. I worked with it for many years and it led me into real time programming.
In 1982, after some time using a cassette recorder as the only mass storage, I bought a Danish disk operating system called PolyDos. With its two 360 KB floppy disks it boosted the size of the programs I was able to write, and it was easy to learn. Soon I designed a hard disk controller for it and in the early 90's, an SCSI controller. Both worked just fine. I also designed a floppy disk controller using the Western Digital WD2793 FDC chip to be able to use higher density disks than was possible with the original NASCOM FDC card. And of course, an EPROM programmer was something I had to have.
After many years of development and programming, this is what my NASCOM looks like. Thanks to the simplicity of the NASCOM, it's quite easy to develop almost any project. Here's a DRAM tester I designed and thought would make me rich... And here's the beginning of a data logger I built for someone whose company might place an order, but no order was ever placed, so the data logger never went beyond the prototyping stage of development.
When the Z280 came along I wanted to design my own Z280 computer, and I actually had a working Z80 keyboard controller, and had bought Yamaha PCDC V6366 chips for the video, had a Z280 assembler ready, and then the Z280 disappeared from the market. And then, finally, the King of them all arrived. The Z380! WOW!
The dream to have a 32 bit NASCOM using the Z380 was now taking shape. I rewrote the assembler, rearranged the interface of the keyboard controller, laid out plans on how to make best use of existing multifunction I/O and video cards, but I wasn't quite happy with the idea of building a computer using components which would soon no longer be available. ISA was on its way into the grave, PCI seemed too complicated and the memory modules changed shape all the time, as it seemed. I just couldn't solve the problem of finding reasonably cheap spare parts over a longer period of time.
The answer was what lots of people before me had already done - make use of that PC! I have always disliked slow RS232 lines, so this is why I chose to communicate through EPP. Of course there is ECP, but EPP is easier and certainly fast enough for present needs.
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